Thank you! I find that the worst bugs are usually the ones involving the logic of the algorithm, and the language has nothing to do with the bug itself. This is why I think that a language that is very explicit, and without side effects and therefor easy to step though using a debugger is desirable.

Buffer over runs, can be trickier, but I have plenty of tooling to find the issues.

Thread safety issues are what nightmares are made of.